Drill boom with rotary adjusting head



Sept. 16, 1969 E. v. KIMBER 3,467,201

DRILL BOOM WITH ROTARY ADJUSTING HEAD Filed May 16, 1968 2 Sheets-Sheet 1 INVIL' T R. Erich VOlJQ|Mi l VL Sept K6,, $9 E. v. KIMBER 3,457,201

DRILL BOOM WITH ROTARY ADJUSTING HEAD Filed May 16. 1968 2 Sheets-Sheet 2 Fig.7

United States Patent 3,467,201 DRILL BOOM WITH ROTARY ADJUSTING HEAD Erich Voldemar Kimber, Vendelso, Sweden, assignor to Atlas Copco Aktiebolag, Nacka, Sweden, a corporation of Sweden Filed May 16, 1968, Ser. No. 729,779 Claims priority, application Sweden, May 19, 1967, 7,081/67 Int. Cl. E21c 11/00, 9/00 US. Cl. 173-36 7 Claims ABSTRACT OF THE DISCLOSURE A drill boom carrying a rotary adjusting head which includes power means for positioning a drilling apparatus carried thereby has a pressure fluid actuated turning means mounted within the boom with a driving member at one end thereof non-rotatably connected to the adjusting head for rotating the latter and the other end thereof non-rotatably connected to the rear end of the drill boom while the inter-mediate portions of the turning means are free from force transmitting engagement with the boom.

This invention relates to drill booms of the type pro vided with rotary adjusting heads adapted for positioning a rock drilling apparatus to different alternative drilling positions with respect to a work surface. In connection with previous embodiments of such drill booms there has been extended a rotation axle for the adjusting head through the entire drill boom and the rotation motor was supported at the exterior of the drill boom and the rear end thereof. Such design poses journalling problems in connection with deflection of the drill boom under load simultaneously with the rear end of the drill boom becoming undesirably bulky. In another known design the drill boom is perforated by longitudinal guide openings in which a torque generating screw is non-rotatably but slidably guided for axial reciprocation. The perforations, however, are apt to weaken the drill boom simultaneously with the latter becoming subjected to undesirable torque.

It is an object of the invention to provide rotation of the adjusting head in a drill boom of the above-stated type by the aid of a turning means built into the drill boom which relieves the drill boom from bulky details and from being loaded by torque at the outwardly projecting jib portion thereof.

For these and other purposes there is according to the invention provided a drill boom with rotary adjusting head adapted for positioning a rock drilling apparatus to different alternative drilling positions with respect to a work surface and comprising a boom support, a hollow drill boom swingably mounted at the inner end thereof on said boom support, a journal bearing at the outer end of said drill boom and axially aligned therewith, an adjusting head having a journal thereon rotatably received in said journal bearing for rotatably supporting said adjusting head thereon, a drilling apparatus adjustably supported on said adjusting head, a pressure fluid actuated turning means within said hollow drill boom and carrying a driving member rotatably at one end thereof, coupling means connecting said driving member non-rotatably to said journal, bracket means connecting the other end of said turning means to the inner end of said drill boom, and the portions of said turning means between said coupling and bracket means being free from force transmitting engagement with said drill boom.

The above and other objects of the invention will become obvious from the following description and from the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. It

should be understood that this embodiment is only illustrative of the invention and that various modifications thereof may be made within the scope of the claims.

In the drawings, FIG. 1 shows diagrammatically a side View of the drill boom with a drilling apparatus as well as an alternative turning position of the latter indicated by broken lines. FIG. 2 shows an enlarged fragmentary vertical longitudinal section of the outer end of the drill boom in FIG. 1. FIG. 3 shows on the same scale as FIG. 2 a fragmentary vertical longitudinal section of the inner end of the drill boom. FIG. 4 is a cross section on the line 4-4 in FIG. 2. FIG. 5 is an enlarged diagrammatic section through a hydraulic lock seen on the line 5-5 in FIG. 3. FIG. 6 is a rear end view on the line 6-6 in FIG. 3. FIG. 7 finally shows on an enlarged scale a fragmentary horizontal longitudinal section through the drill boom in FIG. 1.

In FIG. 1 a drill boom 10 is carried at its inner end swingably vertically and laterally about suitable axles on a boom support 12 which is aflixed to an element 13 forming part of a drill wagon or drill rig, not shown. The angles of elevation and lateral swing of the drill boom 10 are adjusted by means of hydraulic cylinders journalled at the boom support. The drill boom 11 carries at the outer end thereof an adjusting head 14 for mechanized orientation of drilling apparatus including a feed shell 16 provided with a rock drill 15 and a power feed thereon for the rock drill 15. Furthermore there are journalled conventional hydraulic cylinders, not illustrated in detail, on the adjusting head 14 for purposes of positioning the drilling apparatus.

The drill boom 10 includes a straight jib portion 10' shaped as a quadrangular hollow beam. The jib portion 10 has an inner cavity extending longitudinally therethrough and is supported by a short depending angular arm 10 journalled on the boom support 12. The jib portion 10 is provided with flanges 17 and 18 at the ends thereof.

A fork 11 is included in the adjusting head 14 as a carrying member on which the other details of the head are journalled. The fork 11 is affixed by screws to a cylindrical hollow journal 19, FIG. 2, which is turnably journalled in a journal bearing 20 at the outer end of the jib portion 10 in axial alignment with the latter. The journal bearing 20 is carried by a journal sleeve 21 which by flange 22 is fixed to the outer flanges 17 of the jib portion 10 together with a cover ring 23 slidingly surrounding the journal 19. Between the cover ring 23 and the journal bearing 20 is inserted a pair of slide bearing rings 25 disposed at opposed sides of an intermediate flange 24 on the journal 19 and forming an axial bearing which fixes the journal 19 axially with respect to the jib portion 10 The inner end of the journal sleeve 21 is supported by a peripheral support member 26 fixed to the inside of the jib portion 10 at some distance from the outer flanges 17. To the interior of the journal 19 and the inner end thereof there is non-rotatably afixed a gear sleeve 27 provided with an inner coupling means or gear rim 28.

To the inner flanges 18 of the jib portion 10 is screwed a cover 29. The cover 29 provides a bracket to which a pressure fluid driven, preferably hydraulically driven turning means is aflixed for angular adjustment of the adjusting head 14 about the journal bearing 20.

In the turning means 30, FIG. 7, there is generated torque by a drive screw 32 which by helical splines and grooves is in engagement with corresponding splines and grooves on a turning nut 33. The drive screw 32 forms the forward piston rod of a piston 34 which is slidably and sealingly guided in a cylinder sleeve 35. The cylinder sleeve 35 is aflixed by screws to a cylindrical backhead 36 into which the piston 34 projects slidingly but non-rotatably with a rear piston rod 37 provided with straight splines and grooves thereon cooperating with corresponding splines and grooves in the backhead 36. The backhead 36 is closed by a cover 38 screwed thereto and is bolted at a rear end flange 39 thereof, FIG. 3, to the inner side of the bracket or rear cover 29- of the jib portion The cylinder sleeve 35 carries at the forward end thereof a bearing member 40 in which is rotatably journalled a driving member 41. The driving member is carried by a radial ball bearing 42 and is fixed axially at a central flange 43 between a pair of axial ball bearings 44. The bearing member 40 and its bearings 42, 44 are covered by a cover 45 screwed to the bearing member 40 and sealed by suitable sealing rings with respect to the rotatable driving member 41. At the end of a hollow member 46 which projects into the cylinder sleeve 35 ,the driving member 41 carries the turning nut 33.

The driving member 41 carries at the end thereof protruding from the cover 45 a coupling means or gear wheel 47 which is in engagement with the inner gear rim 28 on the journal 19. For purposes of enabling angular movement between the journal 19 and the turning means 30 the gear tops of the gear wheel 47 are spherically rounded at the opposed axial portions of the gear wheel 47 in a manner to give the latter and the gear rim 28 the function of a coupling means providing limited angular movability between the driving member 41 and the joural 19. To the bearing member 40 is connected a pressure fluid conduit 48 by means of which pressure fluid can be supplied via suitable interior channels and openings in the bearing member 40 to the forward end of the cylinder sleeve 35 and to the interior of the hollow member 46 via bores in the driving member 41. By means of another pressure fluid conduit 49 pressure fluid can be supplied via suitable interior channels in the backhead 36 to the inner end of the cylinder sleeve 35 and the interior of the backhead 36. The conduits 48 49 are connected to a hydraulic lock 50 which by means of conduits 48 49 is connected in conventional manner to a source of hydraulic pressure, not shown, via a control value preferably of four way type and likewise not shown which closes the conduit 48 49 or opens one of them optionally to high pressure and the other for return flow.

When pressure fluid is supplied to the conduit 49 the cylinder chamber at the inner end of the cylinder sleeve 35 is pressurized as well as the interior of the backhead 36. As a result the piston 34 is moved by pressure acting thereagainst and against the rear piston rod 37 in outward direction in the cylinder sleeve 35 simultaneously with pressure fluid in front of piston 34 and forward piston rod 32 being expelled via the conduit 48 and the drive screw 32 producing rotation of the nut 33. Thus the driving member 41 is forced to rotate in the bearing member 40 and the rotation thereof is trans mitted via the gear wheel 47 to the journal 19 so that the latter can be adjusted to the desired angle about the longitudinal axis of the jib portion 10 The turning movement is preferably chosen in such way that during a full stroke of the piston 34 outwardly to abutting relation against the hollow member 46 there is performed a turning of the adjusting head 14 through 360. Thus the feed shell 16 and the rock drill can be adjusted to any desired angular position with a full turning circle and may for example be set to the position 16 15 designated by broken lines in FIG. 1. Reaction torque caused by the torque generated between the drive screw 32 and the turning nut 33 is transmitted during angular adjustment via the splines of the rear piston rod 37 to the backhead 36 and thereby directly to the rear cover 29 of the jib portion 10 and the rearmost portions of the drill boom 10. As a result the jib portion 10 is substantially entirely relieved from torque.

When pressure fluid is supplied to the conduit 48 the outer end of the cylinder sleeve 35 and the hollow .4 member 46 of the driving member 41 are obviously pressurized. This causes return of the piston 34 together with the drive screw 32 and the rear piston rod 37 simultaneously with pressure fluid being expelled from the inner end of the cylinder sleeve and the interior of the backhead 36 via the conduit 49 In order to increase the torsional rigidity of the adjusting head 14 in the various adjusting positions thereof there is used a hydraulic lock means 50 working on spring loaded check valves 51, 52. The check valves 51, 52 take up closed position and prevent return flow from the conduits 48 49 when low pressure is maintained in the conduits 48 49 and the control valve, not shown, is disposed in neutral position. Thus the piston 34 will be retained rigidly and hydraulically arrested in any adjusted position between its inner end position shown in FIG. 7 and its outer end position abutting against the hollow member 46. As soon as high pressure is admitted to any of the conduits 48 or 49 by actuation of the control valve, a position slide 53 slidably inserted between said conduits 48 49 in the hydraulic lock 50 opens by the aid of a pushing rod and by way of forced motion the particular check valve 51 or 52 therein which is to be passed by return flow to the other conduit 49 or 48 During deflection of the jib portion 10 due to influence of its weight or of transverse feeding forces, the spherical design of gear wheels 47 allows angular adaptation between the journal 19 and the turning means 30 so that the latter avoids being subjected to excessive load due to flexural stress.

As a modification the backhead 36 in some case may be connected directly to the journal 19 via an elastic coupling in which case the turning means 30 will be mounted in reversed position within the jib portion 10 with the driving member 41 directly and non-rotatably connected to the bracket provided by the rear cover 29 of the jib portion 10 The embodiment shown in the figures, however, is preferred due to the more advantageous distribution of weight and the simpler journalling.

What I claim is:

1. Drill boom with rotary adjusting head adapted for positioning a rock drilling apparatus to different alternative drilling positions with respect to a work surface and comprising a boom support, a hollow drill boom swingably mounted at the inner end thereof on said boom support, a journal hearing at the outer end of said drill boom and axially aligned therewith, an adjusting head having a journal thereon rotatably received in said journal bearing for rotatably supporting said adjusting head thereon, a drilling apparatus adjustably supported on said adjusting head, pressure fluid actuated turning means within said hollow drill boom and carrying a driving member rotatably at one end thereof, coupling means connecting said driving member non-rotatably to said journal, bracket means connecting the other end of said turning means to the inner end of said drill boom, and the portions of said turning means between said coupling and bracket means being free from force transmitting engagement with said drill boom.

2. Drill boom according to claim 1 in which said turning means includes torque generating parts provided by cooperating drive screw and turning nut elements, one of said elements being non-rotably connected to said driving member and the other to said other end of said turning means.

3. Drill boom according to claim 2 in which said turning means includes a cylinder sleeve, a pressure fluid actuated piston sealingly guided for reciprocation in said cylinder sleeve and having axially opposed piston rods thereon, one of said piston rods providing said drive screw element and the other being slidably but non-rotatably guided with respect to said cylinder sleeve, and said driving member being rotatably mounted on said cylinder sleeve and non-rotatably connected to said turning nut element.

4. Drill boom according to claim 1 in which said coupling means includes means allowing angular adaptation between said driving member and journal.

5. Drill boom according to claim 4 in which said means allowing angular adaptation are cooperating gear wheel and gear rim elements in which the gear tops of said gear wheel element are spherically rounded in axial direction for allowing said angular adaptation, said gear rim element being connected to said journal and said gear wheel element to said driving member.

6. Drill boom with rotary adjusting head adapted for positioning a rock drilling apparatus to different alternative drilling positions with respect to a work surface and comprising a boom support, a hollow drill boom swingably mounted at the inner end thereof on said boom support, a journal bearing at the outer end of said drill boom and axially aligned therewith, an adjusting head having a journal thereon rotatably received in said journal bearing for rotatably supporting said adjusting head thereon, a drilling apparatus adjustably supported on said adjusting head, a cylinder sleeve and backhead assembly within said drill boom, bracket means fixedly connecting said backhead and thereby said assembly to the inner end of said drill boom, a driving member rotatably mounted on said cylinder sleeve of said assembly adjacent said journal, coupling means connecting said driving member non-rotatably to said journal, a pressure fluid actuated piston sealingly guided for reciprocation in said cylinder sleeve and having axially opposed piston rods thereon one in engagement with said backhead and the other with said driving member, and said piston rods being provided with respectively straight and helical splines and grooves thereon cooperating with respectively straight and helical splines and grooves on said backhead and driving member for causing rotation of said driving member in response to axial motion of said piston.

7. Drill boom with rotary adjusting head adapted for positioning a rock drilling apparatus to different alternative drilling positions with respect to a work surface and comprising a boom support, a hollow drill boom swingably mounted at the inner end thereof on said boom support, a journal hearing at the outer end of said drill boom and axially aligned therewith, an adjusting head having a journal thereon rotatably received in said journal bearing for rotatably supporting said adjusting head thereon, a drilling apparatus adjustably supported on said adjusting head, an elongated cylinder within said drill boom fixedly connected thereto, a driving member rotatably mounted on said cylinder and non-rotatably connected to said journal, a pressure fluid actuated piston sealingly guided for reciprocation in said cylinder and having axially opposed piston rods thereon one in engagement with said cylinder and the other with said driving member, and said piston rods being provided with respectively straight and helical splines and grooves thereon cooperating with respectively straight and helical splines and grooves on respectively said cylinder and driving .member for causing rotation of said driving member in response to axial motion of said piston.

References Cited UNITED STATES PATENTS 1,741,126 12/1929 Gartin 17336 X 1,860,945 5/1932 Nell 173-36 1,860,946 5/1932 Nell 173-36 2,905,442 9/1959 OFarrell 17336 X 2,914,031 11/1959 Fuehrer 17336 X 3,246,706 4/1966 Feucht 173147 NILE C. BYERS, JR., Primary Examiner 

